When four planes were hijacked on a sunny fall morning, easy-to-use blogging services were still few and far between. Yet many who witnessed the horror of the attacks firsthand took to the keyboard to talk with the world.

Horrified Americans used e-mail, instant messages, any available communication tool. But weblogs meant large audiences, not just friends and family, could read those stories from the scene.

“I have a scrap of paper that flew onto my roof,” wrote New Yorker Anthony Hecht. “Typewritten and handwritten numbers in the millions. A symbol of our tragedy. It smells like fire.”

Many bloggers strayed from their normal writing beats to produce a rolling news service comprising links to materials and tidbits gathered by friends.